The discussion of the background of the invention herein is included to explain the context of the invention. This is not to be taken as an admission that any of the material referred to was published, known or part of the common general knowledge at the priority date of any of the claims.
It has been observed that some individuals, in particular children, focus inaccurately when they observe an object which is situated at a short distance away, that is to say, in near vision conditions. Because of this focusing defect on the part of a myopic child which is corrected for his far vision, the image of an object close by is also formed behind his retina, even in the foveal area.
To slow down myopia progression which is due to this focusing defect, it is known to use a myopia-correcting lens which is of the progressive multifocal ophthalmic lens type. An example of such progressive multifocal ophthalmic lens is disclosed in U.S. Pat. No. 6,343,861.
Such a progressive multifocal ophthalmic lens comprises a far vision area, in which the optical power of the lens is adapted to correct the myopia of the wearer when observing far/distant objects, a near vision area, in which the myopia correction is reduced, and an intermediate area which is situated between the far vision and near vision areas, and in which the optical power of the lens varies continually. Such progressive multifocal ophthalmic lenses are adapted for the foveal vision of the weaver.
It has been observed that the efficiency of such progressive multifocal ophthalmic lenses, and more generally the efficiency of myopia control lenses, is highly variable from one wearer to another.
One reason of such high variance is the improper use by the wearer of such myopia control lenses.
Indeed, as most myopic wearers of those lenses are not presbyopic, they do not require any change in power to clearly see near objects and can therefore use any part of a progressive multifocal ophthalmic lens to read or write.
It has been observed that some wearers do not use the proper part of the myopia control lens, in particular when carrying out near vision tasks, thus reducing the beneficial effect of such myopia control lens.
Therefore, there is a need to provide a method that helps the user use properly the myopia control lenses so as to increase the efficiency of such lenses.